Diesel vs Petrol Cars: Which Is More Economically Efficient?

Diesel and Petrol cars have their fair share of differences — but which type of car and petrol would suit you best? Here’s what to know before splurging on the car of your dreams.

It’s a common Singaporean story: Many diligently save for years, in hopes of saving just enough to buy a new car. But we all know how expensive that can be – especially with the price of COEs in recent years. Along with numerous other costs such as car insurance, maintenance costs, depcreciation costs, and road tax, there lies one major dilemma: petrol or diesel?

It is not uncommon at all to struggle with this decision. After all, both petrol and diesel cars come with their own set of perks as well as drawbacks.

The difference in cost is largely caused by the difference in engine mechanics in both types of cars: petrol engines utilise spark ignition while diesel engines tend to use compression ignition.   However, there are other details to narrow down before finding out which type of car gives you the most bang for your buck.

Table of contents

• Petrol vs. Diesel
• Petrol cars vs. Diesel cars
• Pros and cons of petrol
• Pros and cons of diesel
• Frequently asked questions (FAQ)

Comparison: Petrol vs. Diesel

*Accurate as of time of writing. Prices are subject to fluctuation without prior notice.

Comparison: Petrol cars vs. Diesel cars

*Accurate as of time of writing. Prices are subject to fluctuation without prior notice.
¹Actual charges may vary based on car model, expected mileage, insurance provider, etc.

Pros and cons of petrol

Pros:

#1: Introduction of petrol-electric hybrid cars

In recent years, numerous car manufacturers have been introducing their own versions of the motor industry’s latest sensation: petrol-electric hybrid cars. Charged by electricity and powered by petrol, these cars have a higher fuel economy than most ordinary petrol cars, meaning that they can travel longer distances on the same amount of fuel. The Honda HR-V hybrid, for example, can travel up to 459 miles (approximately 739 km) on a full tank of 40 litres.

#2: Lower insurance and maintenance costs

Owing to the use of lighter and comparatively inexpensive materials in petrol cars, the pricing for petrol car repairs and maintenance is often lower than that for diesel cars. Car servicing charges for both types of cars are approximately equal, however, at around S$138 (before GST.) 

Cons

#1: Lower efficiency and fuel economy

Petrol engines have a relatively low efficiency of about 20%, meaning that only about 20% of fuel is used to power the car. Petrol engines have a lower fuel economy as well, meaning that they travel shorter distances than diesel cars using the same amount of fuel. Although fuel economy varies from car to car, petrol cars generally fall on the lower end of the spectrum. For example, the Toyota Corolla Altis G Petrol has a fuel economy of about 16.7 km/litre, only slightly higher than the benchmark for a ‘good’ fuel economy (16.5 km/litre.)

#2: Higher fuel costs

The current average price of petrol in Singapore is S$2.75 per litre. With diesel being priced at an average cost of S$2.57 per litre, petrol car owners will have to spend more on fuel. 

Pros and cons of diesel

Pros

#1: Greater efficiency and fuel economy

Diesel engines have a relatively larger efficiency of about 30%, meaning that about 30% of fuel is used to power the car. This is significantly higher than a petrol engine’s typical efficiency of 20%. Diesel engines have a larger fuel economy as well. This is seen especially in the Toyota Corolla Altis, which boasts a fuel economy of 21.3 km/litre.

#2: Occasional maintenance

Diesel engines are generally far more durable and tend to last longer than petrol engines. Diesel cars can thus go for longer periods between maintenance appointments. You can thus expect to save on frequent maintenance costs.

Cons

#1: Ban on registration of diesel cars from 2025

In an effort towards a more sustainable Singapore, The registration of diesel cars and taxis will not be allowed from 2025 onwards. As part of this effort, one can expect a possible decline in services offered towards diesel cars in the next few years.

#2: Additional taxes

Diesel car owners are subject to an additional ‘Special’ Tax imposed by the Singapore government on all diesel and diesel-CNG cars. A diesel car owner’s total road tax could thus be up to 6 times the Road Tax of an equivalent petrol-driven car less $100.

Frequently Asked Questions

Q: What is the average cost of fuel consumption in Singapore? 

There are 3 main factors to consider while calculating the average cost of fuel consumption: distance travelled, cost of fuel per litre, and the fuel economy of the car in question.

Fuel economy is a measure of how much distance a car can travel with 1 litre of fuel. Usually measured in km/litre, fuel economy varies from car to car. Generally, anything above 16.5 km/litre can be considered pretty good.  Assuming that the average Singaporean drives a Toyota Corolla Altis and travels around 1,500 km a month, the following calculations can be made:

With the Toyota Corolla Altis petrol engine having a fuel economy of 16.7 km/litre, the average Singaporean would need to purchase around 89.8 litres of petrol a month. With petrol costing approximately S$2.75 per litre, would amount to approximately S$247 spent on fuel in a month.

On the other hand, for the Toyota Corolla Altis diesel engine’s mighty fuel economy of 21.3 km/litre, one would need around 70.4 litres of diesel a month. At the time of writing, diesel in Singapore is priced at S$2.70 a litre, meaning that one would spend around S$181 a month on fuel.

Q: Is diesel cheaper than petrol in Singapore?

Currently, diesel is indeed cheaper than petrol, with petrol and diesel being priced at an average of  S$2.75 and S$2.57 per litre respectively (inclusive of applicable taxes and GST.)  However, this trend can be subject to increase or decrease.

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